Grabius stays silent as he takes in the fighter. 

Nature Check: 4

Looking around, he wonders if there might be any way around this guy or if there might be any traps preventing someone from proceeding further.

Investigation: 15

After learning all he could, he stealths back to the group to report what he’s found.

"So Hobgoblins on one side and Mushroom men on the other?"

"I say we let the hobgoblins fend for themselves. Serves them right if they get themselves killed." 

"oh i agree most heartedly, shall we go check out the mushroom man then?"

"Hold your horses, fellas!" Allure continues to whisper for some reason. "We came here to find the gem of whatever. Personally, if I had a week I could not explain how much of a **** I don't give about armed mushrooms and hobgoblins. I say we look around and try to discover if what we're looking for is in immediate vicinity. And if so we get it, I don't care how, but preferably in a quickest way possible and get the hell away from here."

Also in a responsive whisper, “I agree with Allure. Get in and out as quick as possible. But now we’re stuck between a runed rock and a hard place.

If the gem/key was around here, don’t you think we would have seen it? Or surely one of these guys must’ve found it—I know I would’ve pocketed something like that straight away. It would be beyond luck for it to be sitting in a patch of little mushrooms.

So, once again, I’m guessing we have to get past this ‘Fungi Fighter’. If you recall though, the hobgoblins mentioned something about not losing our heads to these things. With the cloud I saw around this guy, I’m not too keen to get up close and personal right away. I’m open to ideas, but I’m assuming we all can’t sneak past. So, ideas?”

Grabius pulls out one of the small mushrooms and continues inspecting it.

Further inspections reveal nothing more of our suspicious specimen. It seemed to Grabius that the large mushrooms beside the human mushroom were... moving. He also gets a delayed, yet vague memory of a similar creature.He knows that they are called myconids, they comunicate with rapport spores. This is a form of telepathy passed via inhaling spores. When someone inhales a myconid's spores they can speak telepathically.

I assume Grabius shared this knowledge? If not, correct me.

"Telepathically? There is one part of my body I don't want anyone entering and that's my head," said the tiefling. "But I suppose you're right. Ugh."

Allure stared at the myconid, waving his tail uncertainly.

"I suppose we could try the demon thing again, but with adjustment. Tell him I and my "loyal servants" offer help, but a bargain must be struck. And we could demand a gem in exchange, but he could realize I'm not actual demon. Or he could believe me and attack - who knows what they think of the Lower Planes denizens. Shit... Okay, let's keep the plan in mind in case no one can figure out anything else. Ideas?"

Yes, I would have shared all useful knowledge in my report. I figured the little mushrooms probably had some connection which is why I was looking them over again.

"I don't think we'll get around him, so it's either talk or fight. The way the other mushrooms were moving, I would venture to guess he has some sway over them. If they're all sentient, we could potentially get outnumbered fast. So perhaps we could 'reason' with him like Allure suggested? I'm not bad at exchanging words, but much better if I can get a chance to land a good hit. Perhaps I can get into a good position in case things go south... Either way, and while I don't trust those hobgoblins, I wouldn't be too eager to go all telepathic and let them get into our heads right from the start."

"A good fight is second only to a good talk.   Shall we proceed then?"

"I am always willing to fight, but diplomacy is also a part of war. I say we talk first." 

"Fair enough." In a low gravelly voice, Grabius mutters to himself, "Faburan ark hunaran beti bi ark hunaran." As a pleasant smile quickly comes and goes. [If you know Thieves Cant, I'll reveal the phrase]

"So who's takin' charge? Allure? I can help join ya in case things go sideways."

The mushroom man swings his sword around, as if training. Each time he swings the sword you notice he's off balance.

"doesnt look too much of a professional does he"

"It's fine, I'll take point," Allure says. "Just so we're clear, we're just talking, right? No one wants to get behind the guy while I speak and get stabby or something like that? You would actually prefer to deal with him?"

"agreed  talk first

and well see where that goes-hopefully out of this place"

“I’m all for putting the ol’ pig poker to use, but it seems like the consensus is to reason with him. After all, I’d hate to kill him before he learned how to properly use a weapon...” Grabius glances towards the mushroom man again.

The mushroom man seems exhausted from play-fighting.

"lets approach while it seems tired"

Sorry, had no Internet yesterday.

Allure approaches the walking mushroom.

"Greetings and well met. Name's Allure, I'm a traveler here. I was wondering if I could ask you something," he says in the most suave voice he can muster, realizing too late that telepathic mushrooms could not care less about his voice.